The present invention is related to a paper stopper mechanism for paper-feeding apparatus of an office machine, and more particularly to a paper stopper mechanism movable between a first position and a second position by means of frictional force.
A conventional office machine such as a printer is equipped with a paper-feeding apparatus to feed papers into the office machine for faxing, printing or scanning operation. FIG. 1 shows a typical paper-feeding apparatus 10 including rollers for picking and feeding documents or papers p into the machine. In order to truly feed the papers p through the paper-feeding passage 13, a paper stopper mechanism 20 is disposed between the paper-feeding roller 11 and the pickup roller 12. The paper stopper mechanism 20 includes a stopper plate 21 for abutting against front edges of the papers p and keeping the papers p in their true positions before picked up. This can avoid deflection of the papers p in the delivery process or failure of delivery.
When the paper-feeding apparatus is driven to pick up and feed the papers, the stopper plate 21 is moved away as shown by the phantom lines of FIG. 1, permitting the papers p to successfully enter the paper-feeding passage 13. This is accomplished by means of an electromagnetic coil and a cooperative complicated controlling program. Therefore, the paper-feeding apparatus and the paper stopper mechanism are manufactured at high cost.
Another type of conventional paper stopper mechanism employs multiple step motors to respectively control the movements of the gear assembly of the paper-feeding apparatus and the stopper plate. The stopper plate is movable or swingable between a first position and a second position. Two stopper sections (such as protruding posts) are disposed in the first and second positions for stopping the stopper plate at the first and second positions. Accordingly, the movement of the stopper plate is restricted within a set range so as to obviate damage.
However, due to inertia, when the stopper plate is driven by the gear assembly to collide the stopper sections (protruding posts), the stopper plate will rebound from its true position to cause errors. Such errors will sum up to make the stopper plate stop at an incorrect position in follow-up operation. Moreover, such structure is relatively complicated and hard to assemble. As a result, the manufacturing cost is higher.
It is therefore tried by the applicant to provide an improved paper stopper mechanism for paper-feeding apparatus, which can be operated to truly stop at a set position without using any additional transmission mechanism (such as motor) or controlling process. In this case, the structure of the paper stopper mechanism can be simplified to save assembling labor and time. Moreover, without any complicated controlling process or step motor, the manufacturing cost of the paper stopper mechanism is lowered.